Abstract

Although the serotonin hypothesis of schizophrenia is one of the oldest neurochemical hypotheses on the pathogenesis of this disease, it is still highly topical. The concept of how the serotonin system is involved in the origin and progress of schizophrenia has considerably changed over the past decades. Therefore, the present work will give an overview about the development and the current directions of the serotonin hypothesis of schizophrenia. In this regard, we will discuss the phenomenology of hallucinogenic drug action, model psychosis and translational research, post-mortem studies on receptors and transporters, imaging studies, antipsychotic drug action, neuroendocrine challenge studies, platelet and cerebrospinal fluid data, genetic association studies, developmental aspects, and the cross-talk between the glutamate and the serotonin system. In sum, there are several lines of evidence suggesting that the serotonin system plays a major role in the pathogenesis of at least a subpopulation of schizophrenia patients. Further studies are needed to better characterize patients whose psychotic symptoms are suspected to have a serotonergic origin.